.page-about {
  --about-spy-w: 176px;
  --about-gap: clamp(20px, 3vw, 44px);
  background: var(--warm-white);
  color: var(--ink);
  font-family: var(--font-sans);
  overflow-x: hidden;
}

.page-about .eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cinnabar);
}

/* ---------- 面包屑 ---------- */
.page-about .crumb {
  padding-top: clamp(16px, 2.5vw, 28px);
}
.page-about .crumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.12em;
  color: var(--ink);
}
.page-about .crumb__list li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--turquoise-pale);
}
.page-about .crumb__list a {
  color: var(--turquoise);
  text-decoration: none;
}
.page-about .crumb__list a:hover {
  color: var(--cinnabar);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(24px, 4vw, 52px) 0 clamp(32px, 5vw, 68px);
}
.page-about .about-hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 48px);
  align-items: end;
}
.page-about .about-hero h1 {
  margin: 0 0 0.4em;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: var(--fs-display);
  line-height: var(--lh-tight);
  letter-spacing: -0.01em;
  max-width: 12em;
}
.page-about .about-hero__dek {
  margin: 0;
  padding-left: 16px;
  border-left: 3px solid var(--cinnabar);
  font-size: var(--fs-lead);
  line-height: 1.72;
  max-width: 33em;
}
.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--stone);
  border-top: 4px solid var(--indigo);
}
.page-about .about-facts__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px;
  background: var(--warm-white);
}
.page-about .about-facts__num {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(1.5rem, 3vw, 2rem);
  line-height: 1.1;
  color: var(--cinnabar);
}
.page-about .about-facts__label {
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.12em;
  line-height: 1.6;
  color: var(--ink);
}

/* ---------- 档案壳：索引导轨 + 内容区 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  padding-bottom: clamp(48px, 8vw, 96px);
}
.page-about .about-spy {
  align-self: start;
}
.page-about .about-spy__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.2em;
  color: var(--turquoise);
}
.page-about .about-spy__list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-spy__link {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 6px 0;
  font-size: var(--fs-small);
  line-height: 1.5;
  color: var(--ink);
  text-decoration: none;
  transition: color 200ms var(--ease);
}
.page-about .about-spy__link:hover {
  color: var(--cinnabar);
}
.page-about .about-spy__num {
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.14em;
  opacity: 0.68;
}
.page-about .about-spy__link.is-active {
  color: var(--cinnabar);
  font-weight: 600;
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding: clamp(30px, 5vw, 56px) 0;
  border-top: 1px solid var(--stone);
}
.page-about .about-chapter__num {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.2em;
  color: var(--cinnabar);
}
.page-about .about-chapter__lead {
  margin: 0 0 24px;
  max-width: 22em;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(1.35rem, 2.6vw, 2rem);
  line-height: 1.4;
  letter-spacing: -0.005em;
}
.page-about .chapter-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 40px);
}
.page-about .prose {
  max-width: 38em;
}
.page-about .prose p {
  margin: 0 0 1.1em;
  font-size: var(--fs-body);
  line-height: var(--lh-body);
}
.page-about .prose p:last-child {
  margin-bottom: 0;
}
.page-about .prose a {
  color: var(--turquoise);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.page-about .prose a:hover {
  color: var(--cinnabar);
}

/* ---------- 图版 ---------- */
.page-about .about-figure {
  margin: 0;
}
.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  background: var(--stone);
}
.page-about .about-figure--cut img {
  border-left: 2px solid var(--cinnabar);
}
.page-about .about-figure__cap {
  margin: 0;
  padding-top: 10px;
  font-size: var(--fs-small);
  line-height: 1.65;
  color: var(--ink);
  opacity: 0.7;
}

/* ---------- 窄注释栏 ---------- */
.page-about .about-note {
  padding: 18px 16px;
  background: var(--glass);
  border-top: 2px solid var(--turquoise);
}
.page-about .about-note__label {
  display: block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.18em;
  color: var(--turquoise);
}
.page-about .about-note__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
  font-size: var(--fs-small);
  line-height: 1.7;
}
.page-about .about-note__list li {
  position: relative;
  padding-left: 16px;
}
.page-about .about-note__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 8px;
  height: 1.5px;
  background: var(--cinnabar);
}

/* ---------- 升级版深色章节 ---------- */
.page-about .about-chapter--dark {
  margin: clamp(8px, 2vw, 18px) 0;
  padding: clamp(26px, 4vw, 48px) clamp(18px, 3vw, 40px);
  border-top: none;
  background: var(--indigo);
  color: var(--warm-white);
}
.page-about .about-chapter--dark .about-chapter__num {
  color: var(--butter);
}
.page-about .about-chapter--dark .about-chapter__lead {
  color: var(--warm-white);
}
.page-about .about-chapter--dark .prose p {
  color: rgba(251, 246, 237, 0.88);
}
.page-about .about-chapter--dark .prose a {
  color: var(--butter);
}

.page-about .about-vs {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
  margin: clamp(22px, 3vw, 32px) 0 0;
  background: var(--stone);
  border-top: 4px solid var(--cinnabar);
}
.page-about .about-vs__col {
  padding: 20px 18px;
  background: var(--warm-white);
  color: var(--ink);
}
.page-about .about-vs__col--after {
  background: var(--turquoise);
  color: var(--warm-white);
}
.page-about .about-vs__title {
  display: block;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.18em;
}
.page-about .about-vs__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 11px;
  font-size: var(--fs-small);
  line-height: 1.65;
}
.page-about .about-vs__list li {
  position: relative;
  padding-left: 18px;
}
.page-about .about-vs__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7em;
  width: 9px;
  height: 1.5px;
  background: currentColor;
  opacity: 0.6;
}
.page-about .about-figure--abstract {
  margin-top: clamp(22px, 3vw, 32px);
  max-width: 340px;
}
.page-about .about-figure--abstract img {
  border-left: 2px solid var(--cinnabar);
}

/* ---------- 团队协作带 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
  margin: clamp(20px, 3vw, 30px) 0;
  background: var(--stone);
  border-left: 4px solid var(--turquoise);
}
.page-about .about-team__item {
  padding: 20px 18px;
  background: var(--warm-white);
}
.page-about .about-team__tag {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.18em;
  color: var(--cinnabar);
}
.page-about .about-team__item h3 {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.125rem;
  line-height: 1.4;
}
.page-about .about-team__item p {
  margin: 0;
  font-size: var(--fs-small);
  line-height: 1.7;
  letter-spacing: 0.04em;
}

/* ---------- 四条主张 ---------- */
.page-about .about-creed {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  margin-top: clamp(20px, 3vw, 28px);
}
.page-about .about-creed__item {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 28px;
  min-height: 150px;
  padding: 22px 18px;
  transition: filter 240ms var(--ease);
}
.page-about .about-creed__item:hover {
  filter: brightness(0.9);
}
.page-about .about-creed__idx {
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.2em;
  opacity: 0.75;
}
.page-about .about-creed__txt {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.0625rem;
  line-height: 1.55;
}
.page-about .about-creed__item--red {
  background: var(--cinnabar);
  color: var(--warm-white);
}
.page-about .about-creed__item--green {
  background: var(--turquoise);
  color: var(--warm-white);
}
.page-about .about-creed__item--yellow {
  background: var(--butter);
  color: var(--ink);
}
.page-about .about-creed__item--blue {
  background: var(--indigo);
  color: var(--warm-white);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  margin-top: clamp(30px, 5vw, 60px);
  padding: clamp(22px, 4vw, 42px);
  background: var(--glass);
  border-left: 4px solid var(--turquoise);
}
.page-about .about-next h2 {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-section);
  line-height: 1.3;
}
.page-about .about-next p {
  margin: 0 0 20px;
  max-width: 34em;
  font-size: var(--fs-body);
  line-height: var(--lh-body);
}
.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-next__links a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding-bottom: 3px;
  border-bottom: 1px solid currentColor;
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--cinnabar);
  text-decoration: none;
  transition: color 200ms var(--ease);
}
.page-about .about-next__links a::after {
  content: "→";
}
.page-about .about-next__links a:hover {
  color: var(--cinnabar-deep);
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 768px) {
  .page-about .chapter-grid--split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
  }
  .page-about .chapter-grid--note {
    grid-template-columns: minmax(0, 1fr) 232px;
    align-items: start;
  }
  .page-about .about-facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-vs {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-creed {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-creed__item {
    min-height: 178px;
  }
  .page-about .about-chapter--dark .about-figure--abstract {
    margin-left: auto;
    margin-right: 0;
  }
}

/* ---------- 桌面：索引导轨固定 ---------- */
@media (min-width: 1024px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(32px, 5vw, 72px);
  }
  .page-about .about-facts {
    align-self: end;
  }
  .page-about .about-shell {
    grid-template-columns: var(--about-spy-w) minmax(0, 1fr);
    gap: clamp(28px, 4vw, 56px);
  }
  .page-about .about-spy {
    position: sticky;
    top: calc(var(--cmdbar-h) + 28px);
  }
  .page-about .about-spy__list {
    display: grid;
    gap: 0;
  }
  .page-about .about-spy__link {
    padding: 8px 0 8px 14px;
    border-left: 2px solid transparent;
    transition: color 200ms var(--ease), border-color 200ms var(--ease);
  }
  .page-about .about-spy__link.is-active {
    border-left-color: var(--cinnabar);
  }
  .page-about .about-chapter__lead {
    margin-bottom: 28px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-creed__item,
  .page-about .about-spy__link,
  .page-about .about-next__links a {
    transition-duration: 0.01ms;
  }
}